With all of his recent tweeting and tabloid coverage, it's a wonder John Mayer had time to write new music -- much less the best and most adventurous of his four studio albums. Three years after his double-platinum album "Continuum," the new release, "Battle Studies," finds Mayer musing about "finding ways to keep the good alive" in romance. He also marches into fresh stylistic terrain by sampling an anthemic U2 ambience on "Heartbreak Warfare," weaving Beatles-esque textures into "All We Ever Do Is Say Goodbye" and creating smooth Southern California pop melodies on "Half of My Heart" (featuring Taylor Swift). Mayer also puts a funky, sinewy spin on Cream's arrangement of Robert Johnson's "Crossroads." He has raised some eyebrows by asking, "Who says I can't get stoned?" (on the album's first single, "Who Says"), but the rest of the collection has the goods to eclipse that overblown controversy.

ARTIST: MORRISSEY

ALBUM: SWORDS (Universal Music)

Most of the songs on Morrissey's B-sides collection, "Swords," aren't new, but the set is a varied trove of material recorded since 2004 that wasn't included on the former Smiths frontman's most recent three solo albums. There's a lot of piano and torch here, and plenty of the 18 tracks follow classic Moz formulas, putting wistful lyrics against melodic optimism. But the songs also show the artist's continued creative stretch, from the staggered orchestral layers of "The Never-Played Symphonies" to the ambient "Sweetie-Pie," on which Morrissey's normally careening vocals are more a cantor's eulogy. On "Shame Is the Name" (a B-side to the 2009 single "I'm Throwing My Arms Around Paris") Pretenders frontwoman Chrissie Hynde joins on vocals -- a brilliant concept that is sadly underexploited in the mix. From the range of production styles to the bonus disc of live tracks, "Swords" is a welcome catalog addition.

ARTIST: THE BLIND BOYS OF ALABAMA

ALBUM: DUETS (Saguaro Road Records)

The Blind Boys of Alabama have been in business for generations, but only during this decade has the enduring gospel group achieved broader recognition and acclaim. Much of that has come through the alliances the Blind Boys have made with artists from Ben Harper to Travis">Randy Travis, both of whom appear on the group's latest release, "Duets." Only four of the 14 tracks are new, but many -- like the lovely "Magnificent Sanctuary Band" (featuring Susan Tedeschi) -- may be unfamiliar to Blind Boys fans. That track was culled from an album issued by the featured artist, but the previously unreleased cuts make for some of the most exciting moments. With the help of Toots & the Maytals' Frederick "Toots" Hibbert, the Blind Boys meld nyabinghi reggae and gospel on "Perfect Peace," while a collaboration with bluesman John Hammond on "One Kind Favor" sounds like a doom-filled soundtrack to a midnight bayou tour. Other guest spots include performances by Lou Reed ("Jesus"), Bonnie Raitt ("When the Spell Is Broken") and Jars of Clay ("Nothing but the Blood").

ARTIST: JULIAN CASABLANCAS

ALBUM: PHRAZES FOR THE YOUNG (Cult Records/RCA)

Strokes frontman Julian Casablancas steps out with his debut solo album, "Phrazes for the Young," and dynamically weaves '80s techno-pop with psychedelic punk, while also reinventing his usual monochromatic croon. His punk attitude is evident on the opener, "Out of the Blue," on which he sings over upbeat guitar and bright synths, "I know I'm going to hell in a leather jacket/But at least I'll be in another world while you're pissing on my casket." The first single, "11th Dimension," has an old-school dance vibe, complete with electro pulses and enough vocal irony to maintain the cool factor, while "4 Chords of the Apocalypse" is a bluesy number that explodes into a woeful wail. The bleak drums on "Ludlow St." segue into jangly guitars as Casablancas boozily mourns New York's gentrified Lower East Side, proving that he can still orchestrate his own musical hangover.

Most modern listeners identify African-American gospel with recordings that mix passion with professionalism, and perhaps a certain amount of studio smarts. But that ignores the pre-war tradition of street-corner preachers, as well as the small groups that sound as though music isn't coming to them but through them. This three-disc compilation collects 80 recordings of various unpolished styles, in all their haunting glory. Some are peaceful, others pretty, while a few sound downright scary. Much of this music is influenced by, if not made in the shadow of, other styles. One standout is Elder Beck's anti-rock track "Rock and Roll Sermon," a 1956 tirade against the pop music scourge of the day. As the liner notes point out, "It rocks harder than most any rock music in its day." This smartly curated collection is essential for anyone interested in gospel and good fun for those who aren't.

Dolly Parton has spent her career veering between mountain music tradition and Nash-Vegas glitter -- what else would you expect from an artist who built an amusement park near her Appalachian hometown? Her first career-spanning boxed set, "Dolly," captures the highlights of Parton's improbable American journey, with a focus on her early recordings with Porter Wagoner and solo '70s hits like "Coat of Many Colors" and "Jolene." This four-disc set follows Parton through the '80s, when she strayed from her strengths on crossover hits like "9 to 5" and "Islands in the Stream," then returned to her roots on the Ricky Skaggs-produced "White Limozeen." Unfortunately, the set's last songs are from the early '90s. Since then, Parton has gone full circle yet again, recording three critically acclaimed bluegrass albums for Sugar Hill, then abandoning that aesthetic on the appropriately named "Backwoods Barbie." Perhaps that's a story for another set, however, and newcomers and fans alike will find this one remarkably satisfying.

ARTIST: TECH N9NE

ALBUM: K.O.D. (Strange Music)

Out of adversity comes strength. That's the message independent stalwart Tech N9ne delivers on his most introspective project to date, "K.O.D." On the set, he raps his way through a vivid journey to hell and back chronicled in three acts: "Anger," "Madness" and "The Hole." Spurred by his mother's health problems, Tech N9ne's emotional journey also speaks to the pain, fear and helplessness that all of us have experienced at some point in our lives. The unflinching opener, "Show Me a God," dramatically sets the stage as Tech N9ne -- accompanied by Three 6 Mafia and Strange Music colleagues including Krizz Kaliko and Kutt Calhoun -- creatively winds his way past "Demons," "Horns" and "Shadows on the Road" and back into the light: the self-affirming title track, which stands for "king of darkness." Tech N9ne's engaging flow, theatrical rhythms and pithy lyrics make for a nuanced and memorable ride. Who says there's no substance in hip-hop anymore?

ARTIST: RUPA & THE APRIL FISHES

ALBUM: ESTE MUNDO (Cumbancha)

Whether it's klezmer, cumbia, ska, reggae or French chanson, there doesn't seem to be a genre that the San Francisco quintet Rupa & the April Fishes can't do. Lead singer Rupa Marya sings in French, English and Spanish, and gets authentic musicality out of each. The songs are often serious, tackling the longing of immigrants separated from their loved ones. The lengthy flute-and-tabla intro to "Soy Payaso" gives way to a rollicking sound that recalls "Fiddler on the Roof" (but in French). The beauty of "Este Mundo" is how the trumpet, accordion and strings can express melancholy and boisterous joy on a hairpin turn.